1. Field of the Invention
This invention pertains generally to network communication systems, and more particularly to home networking of streaming audio-video content.
2. Description of Related Art
It is of ever-increasing importance to provide reliable mechanisms for streaming video and/or audio content over a network, such as from a server to a client. Often, however, signal interference or degradation in the transmission medium limits this ability, wherein the network is either unusable or has a lower quality of service or bandwidth than desired. Numerous applications exist for communicating streaming data between devices on a network.
By way of example, home networking devices can be configured for communicating audio-video streams, such as between home video servers streaming movies to non-intelligent (“dumb”) terminals within the same home environment. It will be appreciated that applications such as streaming media in the home environment have stringent quality of service (QoS) requirements. For example, for a given packet data rate, the packet error rate (PER) and bit error rate (BER) must be kept sufficiently low wherein the incidence of dropped packets is minimized so that it does not noticeably detract from picture quality for a given packet data rate. In addition, jitter and latency must be minimized to maintain desired picture quality and for additional reasons (i.e. provide acceptable performance when transmitting packets for video-conferencing and teleconferencing.)
The use of “portable” connectivity solutions, such as wireless (i.e. WiFi™, Bluetooth™, etc.) and even power-line connectivity (i.e. Homeplug™), are increasing in popularity as they do not require the installation of dedicated wiring (i.e. Ethernet cabling) or other infrastructure. However, unlike dedicated wiring, these links are subject to various forms of interference.
Previously, maintaining quality of service on these links has been attempted on an individual channel-by-channel basis. For example, in attempting to compensate for dynamically changing network capacity, the transmission rate for a WiFi link is decreased when the transmission PER increases. Maximum ratio combining and multiple input multiple output (MIMO) techniques are also utilized within WiFi networks. In addition, some wireless systems utilize additional techniques, such as switching techniques wherein if a transmitter is unable to perform packet transmissions on a first antenna it switches to a second antenna on the receiver. However, these systems do not always acceptably increase the quality of service for a given data packet rate.
It will be appreciated, therefore, that a need exists for a system and method of maintaining high levels of quality of service despite variations in signal conditions. The present invention fulfills that need, as well as others, and overcomes drawbacks inherent with previous solutions.